My water is still very clear and I am able to inspect my fish very closely during feeding time. I am easily able to identify 4-5 individuals by their heron scars. Anyway, tonight I noticed that 75% of my LMB have a red patch at the base of their caudal fin. Their behavior seems normal and growth rate is good. The spawn has ended although I noticed one fish on a bed tonight. Two weeks ago this condition was limited to 3-4 fish, which I thought was from being caught. What gives?